Plastic film bag and method of filling the same



Dec. 27, 1960 w. B. FOSTER 2,966,414

PLASTIC FILM BAG AND METHOD OF FILLING THE SAME Filed Feb. 23, 1956 Mg'5 RSI '2- INVENTOR: WILLIAM B. FOSTER BY FIG.5 g g a ATT'YS William B.Foster, Minneapolis, Minn. (7212 Hillcrest Drive, Wauwatosa 13, Wis.)

Filed Feb. 23, 1956, Ser. No. 567,206 2 Claims. (Cl. 99-174) Thisinvention relates to improvements in plastic film bags and method offilling the same for use in the frozen food industry and the like, thebag being made preferably of fiat tubular polyethylene material or othersuitable plastic film with similar characteristics, and the bag beingopen on one end and closed on the other end, the closed end having atapered or parabolic shape in the outline of the flat bag form.

The improved bag is preferably made out of flat tubular stockpolyethylene material or the like and the end of the bag opposite theopening therein is tapered at the sides so that the cross section of theopened bag, adjacent the closed end, will be less in area than thecorresponding sections of the articles to be packed into the bag.

A feature of my invention resides in providing such .a bag made ofplastic material which has the property of being able to stretch to acertain degree and yet have a constant tendency to return to itsoriginal shape.

It is also a further feature of my invention to provide an improvedmethod of using a bag of plastic material and of the shape hereinbeforeset forth which does not require the packed or filled bag to be immersedin a liquid heating bath or a heated chamber to cause the bag to shrinkaround the article which has been inserted therein for the purpose ofcausing the bag to fit tightly about the article.

My improved packing method is easily carried out in an economicalmanner, and it is a further feature of the invention to use the articlebeing packed and the stretchability of the bag material to force the airtrapped in the closed end of the bag during the insertion of the articleand thus eliminate the need for vacuum pack-aging. This is accomplishedby pulling the bag over the article whereby the film of the bag isstretched to accommodate the article and air in the bag is forced to theopen end and out of the bag mechanically.

A further feature of my plastic film bag and method of filling the sameresides in providing a simple means of loading the article into the openend of the bag and then pulling the bag over the article. The methodincludes gripping the open end of the bag between roller members whichare formed with axially spaced annular grooves or channels, the rollermembers engaging the outer faces of the bag to pull the bag over thearticle and simultaneously forcing the air past the body of the articleand through the annular grooves or channels of the gripping rollers. Thefilm stretches during the pulling of the bag over the article and isdrawn tightly against the contour of the article whereby it is held bythe inherent tendency of the bag film to elastically return to itsoriginal state.

When the bag has been completely pulled over the article to tightly fitthe article into the bag, the operator, manually or otherwise, forms thefilm of the bag around the exposed end of the article so as to close thebag tightly over the article and then the operator twists the excessfilm to seal the bag. This seal is then-fixed with Sttes atent "ice asuitable metal clamp or clip, or other sealing means.

It is important in the process of packaging and storing frozen poultryand other edibles in plastic film bags to exhaust any excess air aroundthe article and also to virtually hermetically seal the article withinthe bag. I have developed the shape of my bag to tightly receive thearticle and as the bag is stretched over the article in the packingprocess the article is thereafter elastically constrained within the bagto be tightly enveloped as by a second skin.

Air that is trapped by the article escapes around the article toward thenormally open end of the bag, and then through the grooves in therollers used in drawing the bag over the article. In my packaging methodthe article does not move into the bag, but rather the bag moves overthe article. My method also causes the wing tips and books of a dressedfowl to be held against the birds body without forming sharp protrusionsor air pockets and without causing undue breakage of the bag.

A specific embodiment of this invention and a form of means for carryingout the improved method are shown in the accompanying drawings in which:

Figure 1 illustrates my improved bag within the closed end thereof issubstantially parabolic in shape, similar to an intersection of a conewith a plane parallel to its side, to provide a tapered or restrictedportion of less volume than the article to be packed.

Fig. 2 illustrates the first step of carrying out my method wherein adressed fowl or bird is being loaded into my improved plastic bag.

Fig. 3 illustrates the next step of packaging the dressed fowl, theapparatus being illustrated diagrammatically to show the carrying out ofmy method of mechanically evacuating the bag and shaping the packagedarticle by pulling and stretching the bag over the article.

Fig'. 4 illustrates a dressed turkey which has been completely insertedinto the stretched or tensioned bag and the bag hermetically sealed, thebag fitting skin tight over the turkey and substantially all of the airhaving been exhausted out of the bag, and

Fig. 5 is a diagrammatic side view showing the bag pulling rollers andshowing the bag with the bird therein rotated to form the excessmaterial at the opening of the bag into a bag sealing rope-like twistfor attachment of a holding clip closely adjacent the body of the bird.

The invention primarily includes the pulling of a bag of stretchableplastic material over the article to be packed so that the article fitstightly in the bag and the air around the article is virtually entirelyexhausted during the bagging procedure, the bag itself being of lessvolumetric capacity, in its unstretched form, throughout the majorportion that is to contain the packed article. The drawings illustratein Figure l the improved plastic film bag 10 which I use in carrying outmy new pack-aging method. This bag 10 is preferably made of seamlesstubular polyethylene material having a thickness of approximately twothousandths of an inch, and the sides of the tube at the closed end areintegrally sealed along the cut side edges 11 which form the taper whilethe other end of the bag is left open at 12. The closed end 13 of thebag opposite the open end 12 is shown as being substantially parabolicin shape 'to provide the taper or volume restriction of the closed end,the cut sides of the bag converging to meet at a rounded tip or point.

When the bag 10 is unfilled the opposite walls thereof lie flat againsteach other as shown in Figure 1. The over-all size of the bag, however,is of primary importance in that its width should be such that theopened bag, at least in the article containing portion thereof, will beof less volume that the article so that the material of the bag muststretch in substantiallyall directions to accommodate the article.Further, insofar as packaging dressed fowl is concerned, the shape ofthe bag with the tapered or parabolic end 13 is important in that itpermits the bag to fit tightly around the body of the bird, andautomatically force the body into a compact butterball shape mostsuitable and attractive for shipping, handling and display purposes.

To assist in describing my method of filling the bag, I have illustratedin Figure 2, a chute number 15 supported on the base 16 showing the openend of the bag wrapped over the end of the chute and illustrating aturkey 14 being loaded into the bag. The surface of the chute ispreferably wet or moist to facilitate the easy insertion of the turkeyinto the open end of the bag.

The bird is pushed manually into the bag until wholly enclosed and thenthe loose or open end of the bag 10 is inserted between the rollers 17and 18 of the packaging machine, as shown in Figure 3, while theoperator holds the bag in position adjacent the rollers on the inclinedshelf 19 with the tapered end of the bag 13 resting in the saddle 20.The operator helps milk the bag over the bird as the rollers push thebird into the bag and at the same time pull the film over the bird. Asuitable power means operates the rollers 18 to draw the bag over thearticle, the article remaining vertically stationary while the bag ispulled over the same, whereupon, when the article becomes fully andtightly enveloped by the film of the bag, the open end of the bag istwisted to form the cord-like closure tuft 21 and a clamping band 22 ofany suitable nature is applied. The clamping member 22 is located closeto the body of the article in the bag 10 so that the body of the bag isdrawn and held tightly over the upper end of the article and the articleis virtually hermetically sealed in the bag as illustrated in Figure 5.The bag '10 is preferably transparent so that the article therein isclearly displayed through the sides of the bag. Also, any suitable text,trademark and the like, may be printed on the bag. The excess materialabove the clamp 22 is preferably cut away about an inch or so above themetal clamp leaving the short tuft end as shown at 21 in Figure 4.

The chute 15 for loading the bag 10 and the clamping only for thepurpose of setting forth the steps of my method to clearly describe thesame. It will be apparent of the twisted end of the bag 10 in themselvesare not part of my method but drawing and stretching the bag to tightlyenvelope the bag article, as by a tight fitting skin, is a primaryfeature of my method. When the article is contained within the bag 10 itis ready for display, storage, or quick freezing as may be desired.

It will be apparent that my improved plastic film bag may be used tocontain any article desired; however, it has been designed primarily toreceive products which are to be quick frozen and which may be displayedthrough the sides of the bag and where it is desirable to store thefrozen product for a period of time.

My plastic film bag is ideal for soft articles of irregular shape, suchas turkeys and other fowl, barns, and substantially any other productswherein it is desirable to pull the plastic bag tightly over the articleinserted within the same and where any excess air around the 5 articlecontained therein is desired to be eliminated.

My improved bag may be fabricated from tubular stock of polyethylene orsimilar plastic material which has a low permeability for gas or vaporand which is elastically stretchable to permit the bag to be pulledtightly over the article being packed. By providing a stretchable bagthat in transverse section is smaller than the article,

' the packing process causes a compressing of the air in the tapered endof the bag during insertion of the article, and in completing thepacking of the article the compressed air in the tapered end of the bagis caused to automatically produce a slight expansion of the bag aroundthe body of the article so that the article moves quickly to the closedend of the bag to expel all of the trapped air and become tightlyenveloped by the bag. The foregoing objects, description and drawingsare or spot will result in the that the bag used in carrying out mymethod may have any suitable shape of tapered end without departing fromthe spirit of my invention.

Furthermore, my method may be carried out by inserting the article intothe opening of the bag and feeding the open end of the bag between apair of gripping rollers which may remain in closed position and incontact with each other and wherein the body of the rollers are made ofa soft texture of rubber or other suitable material so that when therollers are operated in any suitable manner to cause them to rotate theywill pull the free or open end of the bag between the rollers to drawthe bag over the article. When the rollers have drawn the bag completelyover the article they are stopped rotating and the bag with the articlein it is pulled away from the rollers with a portion of the open end ofthe bag remaining clamped between the stopped rollers. While in thisposition the bag with the article therein is rotated to twist the openend of the bag into a rope-like formation 23 (see Fig. 5) whereupon theclamp 22 is applied thereto closely adjacent the article in the bag. Thetwisted free end 23 of the bag then can be cut off a short distance fromthe clamping means which seals the bag. Thus it will be apparent thatthe rollers employed in carrying out my method to pull the bag over thearticle do not have to be released or moved away from each other but canbe fixed in contact with each other and any suitable means for rotatingthe same can be employed.

The main advantages of my improved method and means for packagingarticles in plastic film bags, reside in the fact that the improved bagand method of filling the same completely obviates the need for the useof any vacuum apparatus to exhaust the air from the bag and completelyobviates the need for any kind of shrinkage apparatus or operation inorder to get a tight fit of the bag around the article package therein;and in the increased rate of packaging production together with thelower cost of the packaging process which may be obtained.

Further advantages reside in the fact that with the use of my improvedplastic film bag of a stretchable elastic material a better shaping ofthe packed product can be obtained which enhances the appearance of theproduct for display purposes and at the same time provides betterprotection for the product during shipping and storage of the same.Furthermore, since the film of the bag is stretched skin tight over thearticle packed therein whereby the film is inherently tending to returnto its original size, any scuffing or breakage of the film at some pointfilm pulling tightly against the article around the margins of the breakor opening, so as to prevent the inward leakage of air or otherdeteriorating factors thereby preventing spoilage of the article exceptin the area of the breakage spot. Still further advantages are to befound in the use of polyethylene films for bag material, which films arechemically and physically inert and do not get brittle under freezer orstorage conditions, and which films are of considerably lesser cost thanother types of material which must have the characteristic of being ableto shrink as'in the case of ordinary materials now being used.

While I have illustrated a particular use and shape of my bag and themethod of filling the same in the foregoing specification and drawings,I desire to have it understood that the invention is not confined to thesame but should be interpreted within the scope of the following claims.

'I claim:

1. The method of packaging dressed fowl which comprises providing anelastic plastic film bag with an opened end and tapered closed end ofgenerally parabolic contour, then drawing the bag over the article andsimultaneously mechanically forcing out the air in thetapered end of thebag and from around the fowl by stretching the bag laterally andlongitudinally over the fowl until the fowl is compressed to rotund formwith the hooks and wings tightly against the body of the fowl and thebag is skin tight thereon, and then twisting the open end of thestretched bag tightly over the fowl and sealing the twisted end closed.

2. The method of packing a dressed fowl for deep freezing and subsequentsale which comprises inserting the fowl, hocks end first, into the openend of an elastic plastic tubular bag having its closed end ofparabolically tapered contour and of less volume in the tapered portionthan the hocks end of the fowl, then drawing the bag over the fowl toforce the fowl into the tapered portion of the bag while simultaneouslystretching the bag laterally and axially into skin tight envelopment ofthe fowl to exclude air from the bag and fold the hooks forwardly andinwardly against the body of the fowl while compressing the hocks end ofthe fowl into a rotund shape, and then twisting the open end of thestretched bag tightly against the breast end of the fowl and sealing thetwisted bag ends.

References Cited in the file of this patent UNITED STATES PATENTS2,071,300 Gammeter Feb. 16, 1937 2,174,924 McCleary Oct. 3, 19392,340,260 'Clunan Jan. 25, 1944 2,664,358 Eichler Dec. 29, 19532,677,487 Friedman May 4, 1954 2,776,216 Thomas Jan. 1, 1957 2,805,973Klasing et a1. Sept. 10, 1957 2,901,875 Hultkrans et a1. Sept. 1, 1959OTHER REFERENCES Poultry Processing and Marketing, July 1954.

1. THE METHOD OF PACKAGING DRESSED FOWL WHICH COMPRISES PROVIDING ANELASTIC PLASTIC FILM BAG WITH AN OPENED THEN DRAWING THE BAG OVER THEARTICLE AND SIMULTANEOUSLY MECHANICALLY FORCING OUT THE AIR IN THETAPERED END OF THE BAG AND FROM AROUND THE FOWL BY STRETCHING THE BAGLATERALLY AND LONGITUDINALLY OVER THE FOWL UNTIL THE FOWL IS COMPRESSEDTO ROTUND FORM WITH THE HOCKS AND WINGS TIGHTLY AGAINST THE BODY OF THEFOWL AND THE BAG IS SKIN TIGHT THEREON, AND THEN TWISTING THE OPEN ENDOF THE STRETCHED BAG TIGHTLY OVER THE FOWL AND SEALING THE TWISTED ENDCLOSED.